aerobeds are incredible, we've got a king size, full size one with built in inflator
John Lewis sell them, they're not cheap but better than anything else I've seen and better than having an ugly sofabed
bigger than my normal bed and very comfy

Without a doubt the Coleman Comfort one.
It really is excellent. No escape of air as you try to get the plug back in.
This weekend either Aldi or Lidl have a mains powered pump that had it up in a minute. And more importantly down again to a nice small size.

Ive got an aerobed platinum kingsize raised, got it for guests but its so good its now my regular bed. Its less sweaty than the memoryfoam I used to use, in fact in cold weather I put a cheap 2.5cm memory foam topper on it as it can be a bit cold. If you just use it for guests it inflates in about 3min and has a valance so it looks like an ordinary bed.
I got it direct from aerobeds site for half price on a special offer (£110)